Combination padlocks typically include a housing part and a padlock shank or shackle. The shank is usually approximately ‘U’-shaped, and the housing part is arranged such that it can receive and retain the ends of the shank in recesses of the housing part.
The housing part houses a combination locking assembly which is operable between a locked configuration and an unlocked configuration. The combination locking assembly includes several dials which are provided with numbers, letters or other characters. The dials can be rotated and aligned with one another and with a feature of the housing part. When an incorrect combination of characters is aligned with the feature of the housing part, the combination locking assembly will be in the locked combination. When the correct combination of characters is aligned with the feature of the housing part, the combination locking assembly will be in the unlocked configuration.
When the combination locking assembly is in the locked configuration, the ends of the shank are held in the recesses of the housing part, such that neither end of the shank can be withdrawn from the corresponding recess. When the combination locking assembly is in the unlocked configuration, the shank can be moved a first distance away from the housing part, such that a first end of the shank is withdrawn from its corresponding recess in the housing part. When the first end of the shank has been withdrawn from its corresponding recess, the shank can be rotated relative to the housing part about the shank's second end, the second end of the shank still being held within its corresponding recess in the housing part.
If a user of the combination padlock wishes to change the combination of characters which unlocks the combination locking assembly (i.e. the ‘correct’ combination of characters for causing the combination locking assembly to be in the unlocked configuration), the user aligns the dials into the current correct combination of characters, so that the shank can be moved away from the housing part. With the dials aligned in the current correct combination, the user moves the shank the first distance away from the housing part, such that the first end of the shank is withdrawn from the housing part. The user then rotates the shank about its second end through a given angle (commonly 90° or 180°).
With the shank rotated to the given angle, the user either moves the shank further away from the housing part (i.e. to a second distance greater than the first distance but such that the second end of the shank is still held within its corresponding recess), or causes the shank to move back towards the housing part (i.e. so that the second end of the shank is pushed deeper into its corresponding recess in the housing part but the first end is not within the first end's corresponding recess).
This action causes the combination locking assembly to enter a combination setting mode. The user may need to apply a force to the shank and/or housing part (e.g. by pulling or pushing) to overcome a bias which attempts to return the shank to a given displacement relative to the housing part (e.g. the first distance). Furthermore, the user may need to continue applying the force so that the shank remains at the required displacement relative to the housing part while the user sets the combination. Alternatively, the user may be able to rotate the shank to an angle at which the shank is held by the housing part at the right displacement (i.e. the shank is held at the second distance or the second end of the shank is held deeper within its corresponding recess).
When the shank is held in the correct position, the combination locking assembly is in the combination setting mode. With the combination locking assembly in the combination setting mode, the user moves the dials to align a new combination of characters with the feature of the housing part.
When the user has aligned the dials in the desired new combination, the user takes the combination locking assembly out of combination setting mode by moving the shank to the position in which it is the first distance away from the housing part, rotating the shank relative to the housing part back through the predetermined angle, and moving the shank towards the housing part so that the first end of the shank is received in the corresponding recess in the housing part. The user can then move the dials away from the new combination so that the combination locking assembly moves from the unlocked configuration to the locked configuration.
Causing the combination locking assembly to enter the combination setting mode as described above can be difficult because the steps that the user must take to cause entry into the combination setting mode are not intuitive and are easily forgotten if the user does not perform resetting of the combination frequently.
Furthermore, users are often unsure whether or not the combination locking assembly has successfully entered the combination setting mode, i.e. it is not clear whether the shank has been rotated sufficiently relative to the housing part, and/or it is not clear whether the shank has been displaced sufficiently relative to the housing part, and/or it is not clear whether the user needs to keep the shank and the housing part a certain distance apart from one another or to push the shank and the housing part together in order to cause the combination locking assembly to enter or remain in the combination setting mode.
Additionally, particularly for smaller padlocks, manipulating a padlock through the steps that are required to enter and leave the combination setting mode can be fiddly. This may make it difficult for people—particularly those with limited motor control or low hand strength—to operate a combination padlock.
The invention aims to go some way towards overcoming or at least ameliorating one or more of the above problems.